JPH0563094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a multilayer film capacitor that has a simple exterior, has good moisture resistance, simplifies the process, and is suitable for mass production.

(Prior Art) Recently, small film capacitors using wound or laminated elements, especially chip-type film capacitors, have been put into practical use, and their range of application to various electronic devices is expanding. Along with this, there are increasing expectations for improved performance and cheaper products.

By the way, the conventional manufacturing method for the above-mentioned multilayer film capacitor will be explained based on FIGS. 8 and 9. First, to form an element a, a strip-shaped metallized film b is laminated in multiple layers by winding or the like. ,
After wrapping and attaching a protective film c for protecting and fixing the film b to the upper and lower surfaces of the laminated film b, an electrode layer d is provided by metal spraying to form a mother element, and individual small elements are formed. Cut into a. As shown in FIG. 8, after adhering and arranging a large number of these elements a on the upper surface of the exterior sheet e, thermosetting resin f is dripped between the elements a and a. , Furthermore, as shown in FIG. 9, the other exterior sheet g is attached from above and after the resin hardens,
If necessary, metal spraying is applied to the electrode part again, and the element a is cut between elements a (dotted line part) again to form an element series.
forming individual capacitors.

By doing so, a chip-type multilayer film capacitor having the same performance as a conventional mold type capacitor, which requires a lead frame, an elaborate mold, etc., is produced.

(Problems to be Solved by the Invention) However, according to the above manufacturing method, the protective film c and the exterior sheets e and g are provided on the outside of the laminated metallized film b in separate steps, and the When producing individual elements a from the elements, they are first cut and separated to form a series of elements, and then the series of elements is cut again to form individual capacitors. That is, similar work steps are repeated from the mother element stage to completion. For this reason, workability was extremely poor and mass production was lacking.

Therefore, the present invention has been made in view of the above-mentioned conventional problems.In the winding process of the mother element, an exterior sheet that constitutes a part of the exterior is wound around the mother element, thereby simplifying the manufacturing process and at the same time making it easy to use. The object of the present invention is to provide a method for manufacturing a multilayer film capacitor that is suitable for mass production despite its exterior packaging.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for forming a laminated film capacitor mother element by winding or laminating a plurality of belt-shaped metallized films, etc. An exterior sheet of fiber-filled reinforced plastic such as glass, which has a lower shrinkage rate than metallized film, is integrally fixed to the upper and lower surfaces of the laminated metallized film layer, and The mother element, the electrode surface of which is provided with a sprayed metal layer, is impregnated with a thermosetting resin, and after removing the resin adhering to the surface of the sprayed metal layer by cleaning or the like, the impregnated resin is heated and cured. , cutting the mother element at predetermined intervals in the longitudinal direction to form a large number of elements;
A feature of the present invention is to obtain a unit capacitor in which a cut surface of the metallized film layer including at least a part of the sprayed metal layer of these elements is coated with resin.

(Function) When forming the mother element, by adhering and winding an exterior sheet with a low heat shrinkage rate to the upper and lower surfaces of the laminated metallized film, it is possible to reduce the mechanical impact, thermal effects, and It is possible to provide and strengthen the protector function for the element against moisture and the like. After going through processes such as metal spraying, heat treatment, resin impregnation, and other expensive processes in the form of a multilayer-wound mother element, the mother element can be cut and the cut surfaces coated with exterior melting resin, allowing it to be immediately manufactured into a product. This eliminates duplication of processes and repetition of similar processes in conventional manufacturing methods.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7.

Embodiment 1 FIG. 1 shows a chip-shaped multilayer film capacitor formed by this manufacturing method, and FIG. 2 shows a negative cross section in this figure.
In these figures, 1 is a laminated film capacitor element (hereinafter referred to as a unit element), 2 is an exterior sheet, 3 is a sprayed metal layer, and 4 is a resin.

The unit element 1 has a thickness of 1.5 to 5.0 μm and a width of 4.5 mm.
Two strip-shaped metallized polyethylene terephthalate films 5 with aluminum vapor-deposited on one side are wound up using a winding device (not shown), and laminated mother elements 6 as shown in FIG. 3 are individually cut. It can be obtained by

For the outer layer sheet 2, among glass fiber reinforced plastics having a shrinkage rate lower than that of the metallized film 5 and high heat resistance, a glass epoxy resin sheet was suitable in this example, and was used. Since sufficient heat resistance is ensured, it can sufficiently withstand the soldering heat when mounted on a printed wiring board, as well as the heat treatment described below to impart properties.

The resin 4 is an epoxy resin having thermosetting properties, ultraviolet curable properties, or both properties, and is applied to both sides of the element including a part of the sprayed metal 3, as shown in FIG.

Next, FIG. 5 is a block diagram showing an example of a manufacturing method comparing the main steps of the present invention and a conventional method, and this will be explained.

First, when winding the metallized film 5 onto a winding drum of a winding device, the exterior sheet 2 is wound and fixed at the beginning and end of winding of the mother element. This exterior sheet 2 has approximately the same width as the metallized film 5 and a thickness of approximately 0.1 to 0.2 mm. Appropriate pressure is applied to the laminated metal films 5 and the like by tightening them from the outer circumferential side by winding them up in this manner. In this state, metal spraying is performed on both sides of the ring-shaped mother element 6 to form a sprayed metal layer 3, as shown in FIG. In addition,
This sprayed metal layer 3 is made of a metal containing tin, zinc, lead, antimony, etc., and is polished and cut as necessary to smooth the surface of the metal layer in subsequent steps. Thereafter, this mother element 6 is subjected to vacuum heat treatment, and then pressurized resin impregnation is performed in a vacuum atmosphere. As this impregnating resin, an epoxy resin having thermosetting properties, ultraviolet curable properties, or a combination of both properties is used. Furthermore, after resin impregnation, the surface 3' of the sprayed metal layer, etc. is cleaned, and the resin is cured by a curing method suitable for the properties of each resin, that is, by heating, ultraviolet irradiation, or both. . Thereafter, the mother element 6 is cut by a cutting blade 7 as shown in FIG. 6 at predetermined intervals depending on the capacity. Then, the resin 4 is applied to both end surfaces of the individually cut elements 1 and cured. The portion to be coated is only a part of the sprayed metal layer 3 and the end face 8 of the element including the side surface of the exterior sheet 2. In addition, even if the resin 4 adheres to the exterior sheet 2 at this time, there is no functional problem.

Note that the solderability is further improved by plating the surface 3' of the sprayed metal layer with tin, zinc, or the like. Furthermore, the adhesion of the resin at the peripheral edge of the exterior sheet 2 is more effective for moisture resistance when a portion of the resin 4 enters the fibrous micropores within the sheet.

Because of this process, when compared with conventional processes, the process is simplified because there is no repetition of similar steps.

Example 2 In Example 1 above, the resin was applied to the cut portion so that a portion of the side 9 of the sprayed metal layer 3 was included, but the resin was applied to areas other than those required for soldering. 4 may be attached,
That is, as shown in FIG. 7, the entire cut surface may be coated with resin, thereby further ensuring moisture resistance.

In the above example, two single-sided metalized films were used, but double-sided metalized films and green films may be alternately stacked, or double-sided metalized films coated with resin may be laminated. Furthermore, in addition to polyethylene terephthalate, polysulfon, polyphenylene sulfide, etc. may be used as the film material, and further improvement in heat resistance can be expected.

The exterior sheet of the present invention is basically fixed to the upper and lower surfaces of the laminated film at the same time as the mother element is formed, but it does not necessarily have to be done at the same time. Plastics with additional reinforcement may be applied. Furthermore, the present invention is not limited to the chip type explained in the above embodiments, but can also be applied to a method of manufacturing a multilayer film capacitor using lead wires, and within the scope of the technical idea described in the claims. Various settings can be changed within the settings.

(Effects of the present invention) As described above, according to the manufacturing method of the present invention, a part of the exterior is provided with an exterior sheet when forming the mother element, and after cutting into individual elements, resin is applied to the cut surfaces. By coating, a multilayer film capacitor is formed. Therefore, there is no duplication of steps as in the conventional method, and therefore the steps can be greatly simplified, and a multilayer film capacitor with extremely good moisture resistance can be obtained, making it industrially useful. This is a great invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a capacitor of the first embodiment formed by the manufacturing method of the present invention, FIG. 2 is a cross-sectional view taken in FIG. 1, and FIGS. A partially enlarged perspective view, FIG. 5 is a block diagram comparing the steps of the present invention and a conventional manufacturing method, FIG. 6 is a perspective view showing a part of the cutting process, and FIG. 7 is a capacitor according to the second embodiment. FIGS. 8 and 9 are perspective views showing a part of a conventional method for manufacturing a chip-type multilayer film capacitor. In the figure, 1 is a unit element, 2 is an exterior sheet,
3 is a sprayed metal layer, 4 is a resin, 5 is a metallized film, 6 is a base element, 7 is a cutting blade, 8 is a cutting surface, and 9 is a side portion of the sprayed metal layer.

Claims (1)

[Claims] 1. When forming a laminated film capacitor mother element (hereinafter referred to as mother element) by winding or laminating a plurality of strip-shaped metallized films, etc., the mother element has a shrinkage rate that is lower than that of the metallized film. An exterior sheet of reinforced plastic with fibers such as glass having a low temperature is integrally fixed to the upper and lower surfaces of the laminated metallized film layer, and the electrode surface portion of the metallized film layer is coated with sprayed metal. The mother element provided with the layer is impregnated with a thermosetting resin, and after removing the resin adhering to the surface of the sprayed metal layer by washing or the like, the impregnated resin is heated and cured, and the resin is heated and cured. A unit capacitor is obtained by cutting the metallized film layer at predetermined intervals to form a large number of elements, and coating the cut surfaces of the metallized film layer, including at least a part of the sprayed metal layer, with a resin. Features: Manufacturing method for multilayer film capacitors. 2. The metallized film, etc. uses any one of two single-sided metalized films, one double-sided metalized film and one raw film, or a double-sided metalized film coated with resin. 2. Method for manufacturing a multilayer film capacitor as described in Section 1. 3. The resin applied to the cut surface is a thermosetting resin, an ultraviolet curable resin, or an epoxy-based resin that has both properties.
2. Method for manufacturing a multilayer film capacitor as described in Section 1. 4. The method of manufacturing a multilayer film capacitor according to claim 1, which comprises applying metal plating on the sprayed metal layer after forming each unit capacitor.